introduce an async lock for stdin and stderr

src/console.rs

@@ -4,7 +4,7 @@ use hermit_sync::InterruptTicketMutex;
 
 use crate::arch;
 
-pub struct Console(());
+pub(crate) struct Console(());
 
 /// A collection of methods that are required to format
 /// a message to Hermit's console.
@@ -21,14 +21,16 @@ impl fmt::Write for Console {
 	}
 }
 
-impl Console {
-	#[inline]
-	pub fn write_all(&mut self, buf: &[u8]) {
-		arch::output_message_buf(buf)
-	}
-}
-
+#[cfg(feature = "newlib")]
 pub static CONSOLE: InterruptTicketMutex<Console> = InterruptTicketMutex::new(Console(()));
+#[cfg(not(feature = "newlib"))]
+static CONSOLE: InterruptTicketMutex<Console> = InterruptTicketMutex::new(Console(()));
+
+#[doc(hidden)]
+pub fn _print(args: ::core::fmt::Arguments<'_>) {
+	use core::fmt::Write;
+	CONSOLE.lock().write_fmt(args).unwrap();
+}
 
 #[cfg(all(test, not(target_os = "none")))]
 mod tests {

src/fd/stdio.rs

@@ -2,17 +2,20 @@ use alloc::boxed::Box;
 #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
 use core::ptr;
 
+use async_lock::Mutex;
 use async_trait::async_trait;
 #[cfg(target_arch = "x86_64")]
 use x86::io::*;
 
+use crate::arch;
 #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
 use crate::arch::mm::{paging, VirtAddr};
-use crate::console::CONSOLE;
 use crate::fd::{IoError, ObjectInterface, PollEvent, STDERR_FILENO, STDOUT_FILENO};
 
 const UHYVE_PORT_WRITE: u16 = 0x400;
 
+static IO_LOCK: Mutex<()> = Mutex::new(());
+
 #[repr(C, packed)]
 struct SysWrite {
 	fd: i32,
@@ -95,8 +98,8 @@ impl ObjectInterface for GenericStdout {
 	}
 
 	async fn async_write(&self, buf: &[u8]) -> Result<usize, IoError> {
-		// stdin/err/out all go to console
-		CONSOLE.lock().write_all(buf);
+		let _guard = IO_LOCK.lock().await;
+		arch::output_message_buf(buf);
 
 		Ok(buf.len())
 	}
@@ -128,8 +131,8 @@ impl ObjectInterface for GenericStderr {
 	}
 
 	async fn async_write(&self, buf: &[u8]) -> Result<usize, IoError> {
-		// stdin/err/out all go to console
-		CONSOLE.lock().write_all(buf);
+		let _guard = IO_LOCK.lock().await;
+		arch::output_message_buf(buf);
 
 		Ok(buf.len())
 	}

src/lib.rs

@@ -77,7 +77,7 @@ mod logging;
 
 mod arch;
 mod config;
-mod console;
+pub mod console;
 mod drivers;
 mod entropy;
 mod env;
@@ -95,12 +95,6 @@ pub mod time;
 #[cfg(target_os = "none")]
 hermit_entry::define_entry_version!();
 
-#[doc(hidden)]
-pub fn _print(args: ::core::fmt::Arguments<'_>) {
-	use core::fmt::Write;
-	crate::console::CONSOLE.lock().write_fmt(args).unwrap();
-}
-
 #[cfg(test)]
 #[cfg(target_os = "none")]
 #[no_mangle]

src/macros.rs

@@ -7,7 +7,7 @@
 #[macro_export]
 macro_rules! print {
     ($($arg:tt)*) => {{
-        $crate::_print(::core::format_args!($($arg)*));
+        $crate::console::_print(::core::format_args!($($arg)*));
     }};
 }
 
@@ -23,7 +23,7 @@ macro_rules! println {
         $crate::print!("\n")
     };
     ($($arg:tt)*) => {{
-        $crate::_print(::core::format_args!("{}\n", format_args!($($arg)*)));
+        $crate::console::_print(::core::format_args!("{}\n", format_args!($($arg)*)));
     }};
 }